IMAGINE that you—or, if you prefer, a younger, more reckless version of you—committed a crime. A bar brawl, driving home drunk again, some tax fiddling, getting caught with a more-than-trivial but less-than-kingpin amount of illegal drugs: something, in any event, that got you sentenced to a few years in prison. And say you were offered a choice: you could either spend those years behind bars, or you could get ten lashes. Certainly painful, probably humiliating, but it would be done under close medical supervision by a licensed flogger, and it would be over in minutes. You would recover, except for the scarring, in a few weeks. And you could get on with your life. You may think flogging is barbaric, but is there any question which you would choose if you could? According to Peter Moskos, a sociologist whose previous book, “Cop in the Hood”, detailed his year spent as a Baltimore beat cop: “If flogging were really worse than prison, nobody would choose it.”

The modern American prison system evolved as an alternative to flogging: penitentiaries were designed to “cure” prisoners of their criminality—to render them penitent—rehabilitating them into productive members of society. On this score, as on most others, it has failed. Indeed, prisons seem to cause more crime than they prevent, hardly surprising when you throw a bunch of criminals together with nothing to do and lots of time. Today roughly 2.3m people live in America's prisons, more than live in any American city other than New York, Los Angeles or Chicago. America's incarceration rate of 750 per 100,000 is five times the world average; roughly one in every 31 Americans—and one in every 11 African-Americans—is under some form of correctional control, whether prison, probation or parole.

Some prison inmates are incorrigibly violent and must be kept apart from society, but most are not. They are there to be punished, hence the maxim, “We build prisons for people we're afraid of and fill them with people we're mad at.” Flogging, Mr Moskos argues, would at least let society punish people swiftly and efficiently. Brutal and archaic it may be, but Mr Moskos convincingly argues that America's prison system is at least as inhumane. “If we really wanted to punish people,” Mr Moskos writes, “we could sentence drug offenders to join gangs and fear for their lives; we could punish child abusers to torture followed by death; we could force straight men to have semiconsensual prison-gay sex…All these things already happen, but we just sweep them under the rug and look the other way.”

The system is also broken: entities that profit from incarceration—prison-guard unions and private-prison builders—lobby for longer sentences, while politicians build prisons in poor rural areas. “The cynical among us,” Mr Moskos writes, “might even say we're spending billions of dollars to pay poor rural unemployed whites to guard poor urban unemployed blacks.” And indeed prisons tend to be filled with poor minorities: more than half of all black men without a high-school diploma spend time in jail. Though in recent years a few states have started to roll back against the trend of ever longer, ever harsher sentencing, these efforts amount to little more than bailing out a sinking supertanker with a teacup.

Mr Moskos's proposal begins as a provocation and ends bleakly plausible. But flogging is still flogging. There may exist little political will to legalise drugs or rethink how and why criminals are punished, but America is not about to start whipping people again anytime soon. Perhaps the most damning evidence of the broken American prison system is that it makes a proposal to reinstate flogging appear almost reasonable. Almost.